It hit 27.4c yesterday, and the temperature only fell to 19.5c overnight – which is the average day time temperature for this time of year.
The temperature was due to hit 30c today, 31c on Tuesday and 32c on Wednesday, before cooling off later in the week, when Jersey should see highs of between 20c and 22c.
Islanders are being urged to wear sun cream, drink plenty of water and avoid direct sunlight during the middle of the day.
